What is chalcedony made of? Varieties of cryptocrystalline quartz gemstones What is its hardness? Seven What colors is it made of? Orange, yellow, green, sky blue, blue, purple, pink, white, black, and sometimes multicolored What is its luster? Waxy to glassy What is its streak? White What is its density? 2.6 g/cm cubed What is its crystal structure? Trigonal Cleavage/Fracture- No cleavage, uneven fracture Special Characteristics- This is used in gemstones, worn by the Romans to promote calmness and peacefulness. Where is it found? Mexico, Madagascar, U.S., India, Burma, and Brazil How does it form? Forms over long periods of time as minerals are deposited into the pocket in another form of rock such as granite. Made mostly around volcanic areas. Uses for chalcedony: Good decorative stone; carved into cabochons; make fine gems Is it found in Iowa? No
Chalcedony
What is chalcedony made of?
Varieties of cryptocrystalline quartz gemstones
What is its hardness?
Seven
What colors is it made of?
Orange, yellow, green, sky blue, blue, purple, pink, white, black, and sometimes multicolored
What is its luster?
Waxy to glassy
What is its streak?
White
What is its density?
2.6 g/cm cubed
What is its crystal structure?
Trigonal
Cleavage/Fracture-
No cleavage, uneven fracture
Special Characteristics-
This is used in gemstones, worn by the Romans to promote calmness and peacefulness.
Where is it found?
Mexico, Madagascar, U.S., India, Burma, and Brazil
How does it form?
Forms over long periods of time as minerals are deposited into the pocket in another form of rock such as granite. Made mostly around volcanic areas.
Uses for chalcedony:
Good decorative stone; carved into cabochons; make fine gems
Is it found in Iowa?
No
http://www.mindat.org/min-960.html
http://www.addmorecolortoyourlife.com/gemstones/chalcedony.asp
http://geology.about.com/od/mineral_ident/ig/lusters/qtzcrypt.-0Zl.htm
http://www.all-that-gifts.com/se/chalcedony.html
http://www.wisegeek.com/what-is-chalcedony.htm
http://www.minerals.net/mineral/silicate/tecto/quartz/chalcedo.htm